From Big Medical Encyclopedia

ALARM SYSTEMS — the system of conditioned connections, associations, with the help to-rykh live organisms interact with the environment.

The concept of «alarm system» is entered by I. P. Pavlov in 1932 for an explanation fiziol. patterns of work of a brain is also reflection of the system principles of the organization of functioning of a brain, and also features higher nervous activity (see), allowing an organism to provide the best ratios with the habitat.

Villages of the village play a huge role in human life and animals. The principle of the alarm system is implemented already at the level of protozoa, and all further complication and improvement of adaptive opportunities of organisms considerably is defined by S.'s evolution by the village. In particular, the possibility of timely response to the signal preceding action of biologically essential factor is equivalent to the solution of a question of further existence as this factor can be useful or harmful to this organism.

Any natural physical can become signals of the vital phenomena and objects satisfying this or that requirement of an organism. or chemical agents — sounds, smells, visual objects, etc. On their basis the so-called first alarm system, the general for all fauna forms, including also the person.

The concept «alarm system» — one of central in I. P. Pavlov's doctrine about conditioned reflexes (see). I. P. Pavlov considering conditioned reflexes as a type of associations believed that all behavior of an animal is defined by the level of the organization of century of N of. The first of them combines system instinctive reflexes (see) — food, defensive, sexual, etc., including their such irregular shapes, as instincts (see), inclinations (see) etc. Functioning of these reflexes are the cornerstone mechanisms of genetic memory. Instinctive reflexes are a way of adaptation of an organism by Wednesday, but he is limited by a rigid framework of inborn mechanisms.

The second level of century of N of is presented by an alarm system of the vital factors the accompanying or related natural agents. Being combined with action of unconditional irritants, these mechanism agents conditional, or temporary, bonds (an incentive — a reinforcement) become their signals. Set of such conditioned connections also represents S. of page, edges at animals is only, and the person — the first S. has a page. It provides to an organism ample adaptive opportunities to orientation in the environment.

For the person the first S.'s value of page completely remains. But its evolution differing in such qualitatively new categories as the social relations demanded development of various forms of communication. At first it were gestures, a mimicry, exclamations. Then exclamations began to turn into words, the conjoint speech. On the basis of ability to the highest forms of generalization, abstraction it was created thinking (see), a cut it was enriched with knowledge, created science and art. The person began not only to adapt to the nature, but also to adapt the environment for the needs.

The second S. inherent to the person of page representing the generalizing alarm system in the form of the speech (said, heard), letters, drawing, gestures, etc. was so created (see. Speech ). The word, combining the first S.'s signals to page, becomes a signal of signals; words designate actions, any relationship.

The second S.'s formation by the village is well traced in overseeing by development of children. In the first three years of life the first S. the village and the emotional sphere forms preferential. Ability to higher extent of generalization is developed on 4 — the 5th year of life then the second S. of page becomes defining in the subsequent human life.

Structurally functional providing S. of page differs in complexity. Signal as physical. or the chemical factor is perceived receptors (see) — input devices analyzers (see). In receptors there is a coding of information in the form of the sequence of nervous impulses (see. Nervous impulse ). The nervous code is exposed to primary analysis in transfer relays (the intermediate centers) of a touch path and comes to projective zones of bark brain (see). It is supposed that there the monotouch images corresponding to external influence form, and in the associative fields differing in existence of polytouch elements on the basis of convergence polytouch associations are created: acoustical and tactile, olfactory and flavoring, etc. Such associations are essential to alarm activity, in to-rykh one of components of a difficult image acts as a harbinger, a signal of other part representing the factor, vital for an organism, napr, in the «smell — food» complex the smell perceived as a harbinger of food acts as a natural signal.

Other important link of S. of page are the centers of requirements, excitement or braking to-rykh causes effectiveness or inefficiency of this signal, napr, the flavor of food will not cause a food reflex as the hypothalamic «center of hunger» will be slowed down in a full animal.

Carries out an important role memory (see), storing in coded form copies of touch (sensitive) signs certainly of the operating factors (unconditional irritants) put in it genetically and also all individual life experience gained by an organism.

An end body of activity of S. of page is the direct motive act which is carried out by means of executive bodies — muscles, glands.

The listed and nek-ry other systems of a brain (limbic, basal kernels, etc.) provide its analitiko-integrative activity, on a cut work of alarm systems is based (see. Basal kernels , Limbic system ). At the same time for the second S. pages matter specific areas of bark of a great brain — motor and touch word centers, the centers of reading and the letter, a zone of a projection of lips, language, a throat, etc.

Disturbances in S.'s activity by the village can be caused by the wrong or defective functioning of any of the listed links. Partial or checkmate of this or that touch system, the device of memory, system of activation leads to serious disorders of analitiko-integrative function of a brain.

The second S. of page of the person is especially vulnerable. Defeat of the touch and motor centers, peripheral devices is shown in various dysfunctions of the speech, reading, the letter, graphic ability, recognition of words, objects, i.e. in various forms aphasias (see), apraxias (see), agnosias (see).

Functional and organic lesions of c. N of page cause various nervous and mental diseases. Analogs at animals have the Nek-ry forms of pathology that allowed I. P. Pavlov to give them fiziol. analysis. He emphasized value of types of higher nervous activity (see). Bystry change of excitement by braking, an overstrain of brake process easily cause neurotic frustration in dogs of excitable type (see Neurosises experimental). Chief «suppliers» of neurosises I. P. Pavlov called dogs of weak brake type as they cannot take out either intense excitement, or intense braking. At an overstrain of exciting process such animals fall into the state similar to hysteria. At people, I. P. Pavlov believed, hysteria (see) also the nek-eye is characterized by dissociation of activity of the first and second S. of page. The large role in it is played by development of phase, hypnotic states, at to-rykh influence of emotional «charge» of a subcortex often affects at concentration of nervous processes in bark and their extraordinary «zafiksirovannost».

I. P. Pavlov's assumptions of disturbance of the correct interaction between the first and second S. of page at psychological diseases gained further development in works of A. G. Ivanov-Smolensk and other scientists. From these positions origins of such diseases as neurosises, psychoses were considered (see. Mental diseases ), schizophrenia (see).

It should be noted that dysfunction of the second S. of page is very complex problem. In the analysis of diseases it is necessary to consider interaction of various social factors with pathological; psychological indicators are of great importance, to-rye it is not always possible to explain from positions of physiology.

Methods of a research C. of page are various. It is first of all a classical method of conditioned reflexes in its various modifications with parallel registration of motor and vegetative reactions. Electrophysiologic methods are widely used: electroencephalography (see), an electromyography (see), microelectrode method of a research (see), the activity of separate neurons and their populations allowing to study in combination with the machine mathematical analysis of data (at the person neyronalny activity is registered only in a wedge, conditions with the diagnostic purpose). Also different types of an associative verbal experiment, record of electric activity of the muscles participating in the act of the speech are widely applied. Along with it the data obtained during the studying of the touch and other systems participating in integrative and analytical activity of a brain are used.

Bibliography: Ivanov-Smolensk A. G. Sketches of pilot study of higher nervous activity of the person, M., 1971; Koltsova M. M. Development of alarm systems of reality in children, JI., 1980, bibliogr.; To r and t and Yu. G N. Analysis of signals brain, JI., 1977, bibliogr.; Destroy certain JI. B. Biological bases of rational activity, M., 1977, bibliogr.; About r e l and JI. A. Questions of higher nervous activity, M. — «ii., 1949; Pavlov I. P. Twenty years' experience of objective studying of higher nervous activity of animals, M., 1973; Penfild V. and Roberts L. The speech and brain mechanisms, the lane with English, L., 1964, bibliogr.; Sechenov I. M. Chosen works, t. 1, M., 1952; Firsov L. A. and Plotnikov V. IO. Voice behavior of anthropoids, L., 1981, bibliogr.

Yu. G. Kratin.